Blue basic dye and process of making same.



S'ra'rns PATENT @rnicn.

B'ENNO IIOMOLKA, OF FRANKFORTON-TIIE-MAIN, GERMANY, ASSIGNOR TO THE FARBTVERKE, VORMALS MEISTER, LUCIUS & BRUNING, OF I'IUCHST ON-"HE-MAIN, GERMANY.

BLUE BASIC DYE AND PROCESS OF MAKING SAME.

SPEUIFICATIDN forming part of Letters Patent No. 649,727, dated May 15, 1900.

Application filed February 28,1899. Serial No. 707,188. (Specimens) To all, whom, it may concern.-

Be it known that LBnNNo HOMOLKA, Ph. 1)., a citizen of the Empire of Austria-Hungary, residing at Frankforton-the-\lain, Germany, have invented certain new and useful Improvements in the Manufacture of Blue Basic Dyestuffs Soluble in Tater, of which the following is a specification.

By the American Patent No. 524,252, of August 7, 1897, and the German Patents Nos. 85,932 and 92,015 a series of peculiar blue dyestuffs soluble in water has become known which are obtained if such diazo compounds as result from the action of nitrous acid upon asymmetric dialkylsafranins are allowed to act upon beta-naphthol,whereby safranin and beta-naphthol are employed in molecular quantities. I have found that diazo compounds obtained from asymmetric dialkylsafranins likewise act upon beta-naphthol under certain conditions in such a manner that two molecules of diazotized dialkylsafranin combine with one molecule of beta-naphthol. The compounds thus obtained are blue basic dyestuffs soluble in water which surpass in fastness to washingand alkalies the abovementioned dyestuffs obtained by combining one molecule of diazotized dialkylsafranin with one molecule of beta-naphthol.

As primary material for the practical carrying out of my process I recommend the technical asymmetric dialkylsafranins as manufactured now by anilin works on a large scale and used in the dye industry under various names-such as methylenviolet, clematin, girofl,he1iotrope,&c. These are chiefly, from a chemical point, asymmetric dimethylsafranins and asymmetric diethylsafranins resulting from oxidizing the mixtures of dimethyl-paiaphenylendiamin or diethylpara-phenylendiamin with anilin, sol uidin, or xylidin, or with mixtures of these bases. (Vida Schulz and Julius, fZabeZZarischc Uebersicht cZe-r IQ'ms'tZ. Organ. Fcm'bszfoffc, Berlin, 1897, p. 182.)

I illustrate my process by the following examples: Sixteen parts, by weight, of asymmetric diethylphensafranin (two molecular proportions) are dissolved in one thousand parts, by weight, of water. diazotized in the usual manner at a tempera ture of to centigrade, with 8.62 parts, by weight, of hydrochloric acid of 21 Bauni and 2.76 parts, by weight, of sodium nitrite (NaNO of one hundred per cent. of strength. To the blue diazo solution thus obtained is run, while Well stirring, an alkaline solution of beta-naphthol sodium obtained by dissolving three parts, by weight, of beta-naphthol (one molecular proportion) in 3.8 parts, by weight, of soda-lye (specific weight 1.437) and two hundred parts, by weight, of water. The formation of the dyestuif is complete after several hours standing. It is then heated with steam to 60 to 70 centigrade. The dyestuif is precipitated with common salt and some chlorid of zinc, then filtered, pressed, and dried.

In many cases it is preferable yet not indispensable to carry out theformation of the dyestuif in presence of organic acids, and then one proceeds as follows: Sixteen parts, by weight,ofasymmetric dimethylphensafranin, zinc double salt, (two molecular proportions,)

(CH19N4OD2ZHC12 are dissolved in water and converted with 8.62 parts, by Weight, of hydrochloric acid (21 Baum) and 2.76 parts, by weight, of so- This solution is dium nitrite of one hundred per cent. of

strength (two molecular proportions) into the diazo compound, as above described. To this solution is added ten parts, by weight, of so dium acetate, and then is run in while well stirring an aqueous solution of beta-naphlet powders, soluble in water and alcohol with a violet-blue color, in concentrated sulfuric acid with a green color, and quite insoluble in ether and benzene. The dilute aqueous solutions become green blue on addition of ammonia. Fixed alkalies give in aqueous solutions a green-blue tint or precipitate which is little soluble or nearly insoluble in ether.

Having now described my invention, what I claim is 1. The herein-described process of manufacturing blue basic safranin dyestufis soluble in water, which consists in allowing one molecule of beta-naphthol to act upon two molecules of a diazotized asymmetric dialkylsafranin, substantially as set forth.

2. As a new product, the dyestuff obtained by combining one molecule of bcta-naphthol with two molecules of the diazo compound resnlting from the action of nitrous acid upon asymmetric dialkylsafranin, being a brownviolet powder, soluble in water and alcohol with a violet-blue color, in concentrated sulf uric acid with green color, quite insoluble in ether and benzene, the dilute aqueous solution on addition of ammonia giving a greenblue tint and on addition of fixed alkalies to the aqueous solution a green-blue tint or precipitate soluble with difficnlty or almost insoluble in ether, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

BENNO I-IOMOLKA.

I'Vitnesses BERNHARD LEYDEOKER, WILHELM SCHAAB. 

